1. Field of the Invention
The present invention relates to the field of die handling, semiconductor packaging, assembly, multi-chip modules (MCM), and System-in-a-Package (SiP).
2. Description of the Related Art
One factor in reducing the cost of semiconductor fabrication is maximizing the number of semiconductor die on a semiconductor wafer. The advantage of increasing the number of die on a wafer is typically lost in the packaging or assembly processes of individual die because wafers need to be died and the individual die handled in order to sort good die and subsequently assemble the good die into a package.
A waffle pack is typically used to reduce the amount of individual die handling throughout the packaging process thereby achieving lower production cost and increased throughput. A waffle pack is a container typically with individual recesses to loosely restrict the movement of individual die within a recess and avoid the mixing of die between recesses. Various waffle packs have recesses typically made in various sizes and shapes to accommodate a various number of die and a variety of die sizes. The recesses are typically square, and the number of recesses is typically less than 50 and smaller than the number of die died from a semiconductor wafer. Waffle packs are frequently used to ship or store die after the die are died from a wafer and before they are packaged. Waffle packs are typically used in conjunction with automated pick-and-place tools that pick good die from the died wafers and place them in waffle packs. These pick-and-place tools are also used to pick die from waffle packs and place the die in semiconductor packages. Once loaded into the waffle pack, the die may also be covered with anti-static paper, and a lid is usually used to secure the waffle pack package together.
Consequently, during the assembly of multi-chip semiconductor packages, for example a multi-chip module (MCM) or a System-in-a-Package (SiP), die from different waffle packs are typically required as needed for the different chips of the multi-chip assembly. Although use of the waffle packs avoids handling of individual die throughout the packaging process, a large number of waffle packs is required to accommodate all of the die on a semiconductor wafer. Furthermore, for multi-chip semiconductor packages, a number of different waffle packs is typically required to provide for all the different type of die needed for the multi-chip semiconductor package being assembled. Conventional waffle packs are thus typically simple storage containers for die during intermediate steps in the packaging process.